Fingerprint sensor package and fabricating method thereof

ABSTRACT

A fingerprint sensor package includes a substrate, a fingerprint sensor chip, and a flexible printed circuit board (FPC). The substrate includes a first portion and a second portion. A line layer is disposed on the first portion. The fingerprint sensor chip is disposed on the substrate. The fingerprint sensor chip is electrically connected to the FPC by the line layer. The package is simple, reliable, and easy for manufacturing process, reducing materials and processing costs.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application is a continuation of U.S. application Ser. No.15/228,156, filed Aug. 4, 2016, which claims priority to Chinese PatentApplication No. 201610352261.9 filed on May 25, 2016, the contents ofwhich are incorporated by reference herein.

BACKGROUND Technical Field

The subject matter herein generally relates to a field of data security,and particularly to a fingerprint sensor package and methods forfabricating the fingerprint sensor package.

Description of Related Art

A fingerprint identification chip improves the security of the terminalend-user products such as smartphones, tablet PCs, etc. It is acomplicated and expensive process to etch the conventional fingerprintidentification chips to form a conductive layer. The coating layer onthe finger contact portion, which is easily scratched or contaminated tocause failure of recognition. The combination lines connected with thechip and the substrate typically expose portions between the chip andthe substrate. The chip, the line layer, and substrate must be packagedtogether before bonding to adjacent layers to avoid electricalconnection problems.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described withreference to the attached figures. Many aspects of the disclosure can bebetter understood with reference to the following drawings. Thecomponents in the drawings are not necessarily drawn to scale, theemphasis instead being placed upon clearly illustrating the principlesof the disclosure. Moreover, in the drawings, like reference numeralsdesignate corresponding parts throughout the several views.

FIG. 1 is an exemplary embodiment of a fingerprint sensor package.

FIG. 2 is an exemplary embodiment of a substrate in the fingerprintsensor package of FIG. 1.

FIG. 3 is the substrate in FIG. 2 as seen from another direction.

FIG. 4 is an exemplary embodiment of a fingerprint sensor formed with ablock in the fingerprint sensor package of FIG. 1.

FIG. 5 is an exemplary embodiment of a flexible printed circuit.

FIG. 6 is an exemplary embodiment of the combined fingerprint sensorchip and the substrate.

FIG. 7 is a flow chart of a manufacturing process for a fingerprintsensor package.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures, and components havenot been described in detail so as not to obscure the related relevantfeature being described. Also, the description is not to be consideredas limiting the scope of the embodiments described herein. The drawingsare not necessarily to scale and the proportions of certain parts havebeen exaggerated to better illustrate details and features of thepresent disclosure.

The disclosure is illustrated by way of example and not by way oflimitation in the figures of the accompanying drawings in which likereference numerals indicate the same or similar elements. It should benoted that references to “an” or “one” embodiment in this disclosure arenot necessarily to the same embodiment, and such references can mean “atleast one”.

FIG. 1 illustrates a fingerprint sensor package. The fingerprint sensorcomprises a substrate 1, a fingerprint sensor chip 2, and a flexibleprinted circuit board (FPC) 3. The fingerprint sensor chip 2 iselectrically connected to the FPC 3 through a line layer 13 of thesubstrate 1.

FIG. 2 illustrates a substrate 1. The substrate 1 comprises a firstportion 11 and a second portion 12. The length and thickness of thefirst portion 11 can be less than the length and thickness of the secondportion 12. The first portion 11 has a first surface 110, the secondportion 12 has a second surface 120, and the first surface 110 issubstantially parallel to the second surface 120.

FIG. 3 illustrates a bottom-up view of the substrate 1 of FIG. 2. Theline layer 13 is distributed on the first surface 110 (shown in FIG. 2)of the first portion 11. The substrate 1 can be made of reinforcedglass, sapphire, or ceramic material.

FIG. 4 illustrates a fingerprint sensor chip 2 including a chip body 21and a block 22. The chip body 21 has a third surface 210. In theexemplary embodiment, the chip body 21 can be rectangular. The chip body21 can be any shape. The block 22 is placed on one side of the thirdsurface 210. The block 22 can be a soldering ball or other shapes, theblock 22 can be made of a metal or tin alloy, which is conductive.

FIG. 5 illustrates an FPC 3 including a body 31, a connector 32, and aplurality of SMD components. The connector 32 and the SMD components aresoldered on the body 31, and one end of the body 31 forms a solderingpoint 33.

FIG. 6 illustrates another fingerprint sensor package. The block 22 ofthe fingerprint sensor chip 2 extends out from the third surface 210 ofthe chip body 21 and towards the first surface 110 of the first portion11. The fingerprint sensor chip 2 can be electrically connected to theline layer 13 through the block 22. The block can be fixed on the firstportion 11 by adhesive 4 such as epoxy resin, and part of the thirdsurface 210 can be fixed on the second portion 12 by the adhesive 4.

Referring to FIG. 1, the soldering point 33 of the FPC 3 is solderedwith the first portion 11 and the line layer 13. The fingerprint sensorchip 2 is in contact with the line layer 13 by the block 22, and thefingerprint sensor chip 2 is electrically connected to the FPC 3 throughthe line layer 13.

FIG. 7 is a flowchart illustrating a method for manufacturing afingerprint sensor package according to various aspects of the presentdisclosure.

At S2, a fingerprint sensor chip 2 is manufactured. The fingerprintsensor chip 2 has a chip body 21, and a block 22 is made on the chipbody 21.

At S4, a substrate 1 is manufactured to includes a first stepped portion11 and a second stepped portion 12. A line layer 13 is distributed on afirst surface 110 of the first stepped portion 11.

At S6, an FPC 3 is manufactured. The FPC 3 has a body 31, a connector32, and a plurality of SMD components soldered on the body 31.

At S8, Adhesive 4 is used to connect the fingerprint sensor chip 2 andthe second portion 12 of the substrate 1. The block 22 extends out fromthe second portion 12 and is fixed with the first portion 11 by theadhesive 4 to be electrically connected to the line layer 13.

At S10: the FPC 3 is soldered on the first portion 11 to form a solderpoint 33 electrically connected to the line layer 13.

By the method described in FIG. 7, the FPC 3 is electrically connectedto the line layer 13 by the solder point 33 and the fingerprint sensorchip 2 is electrically connected to the line layer 13 by the block 22.Thereby, the fingerprint sensor chip 2 and the FPC 3 are electricallyconnected.

In an exemplary embodiment, the line layer 13 is positioned on thesubstrate 1 and the fingerprint sensor chip 2 is electrically connectedto the line layer 13 by the block 22. The fingerprint sensor chip 2 doesnot need to be etched. The line layer 13 is placed on the substrate 1 ofreinforced glass and the surface of the fingerprint sensor chip 2 isdirectly fixed on the substrate 1 by adhesive 4 without packaging. Thisdecreases the thickness of the fingerprint sensor chip 2. Thefingerprint sensor uses the reinforced glass instead of coating to avoidscratching, contaminations, etc. The structure of the fingerprint sensoraccording to an exemplary embodiment of the disclosure is simple and themanufacturing method is fast and affordable. The fingerprint sensor chipreceives and detects users' fingers on the substrate made of glass, andthe fingerprint sensor chip is electrically connected to a conductor bychip circuit to process the electrical signals output by the conductor.

Although the features and elements of the present disclosure aredescribed as embodiments in particular combinations, each feature orelement can be used alone or in other various combinations, within theprinciples of the present disclosure to the full extent indicated by thebroad general meaning of the terms in which the appended claims areexpressed.

What is claimed is:
 1. A fingerprint sensor package, comprising: asubstrate having a first portion and a second portion, wherein the firstportion has a first surface, and the second portion has a secondsurface, the first portion is in contact with the second portion anddefines a stepped transition, and the first portion and the secondportion are on both sides of the stepped transition respectively; afingerprint sensor chip comprising a chip body having a third surfaceand a block on one side of the third surface; a FPC; and a line layerdisposed on the first portion, wherein the fingerprint sensor chip andthe FPC are coupled through the line layer, the block extends out fromthe third surface and towards the first surface, and the fingerprintsensor chip is electrically connected to the line layer through theblock.
 2. The fingerprint sensor package of claim 1, wherein the thirdsurface is fixed on the second surface by adhesive, and the block isfixed on the first portion by adhesive.
 3. The fingerprint sensorpackage of claim 1, wherein the FPC comprises a body, a connector and aplurality of surface-mount device components, the connector and thesurface-mount device components are welded on the substrate, and one endof the body forms a solder point electrically connected to the linelayer.
 4. The fingerprint sensor package of claim 1, wherein thesubstrate is made of reinforced glass, sapphire or ceramic material. 5.The fingerprint sensor package of claim 1, wherein the block is a metalor tin alloy conductive material electrically connected to the linelayer.
 6. A method of manufacturing fingerprint sensor package, themethod comprising: providing a fingerprint sensor chip comprising a chipbody and a block made on the chip body; manufacturing a substrate, andcutting the substrate into a first portion and a second portion, andforming a line layer on the first portion, wherein the first portion isin contact with the second portion and defines a stepped transition, andthe first portion and the second portion are on both sides of thestepped transition respectively; providing a FPC comprising a body, aconnector and a plurality of surface-mount device components welded onthe body; combining the fingerprint sensor chip with the second portionof the substrate, wherein the block extends out from the second portionand is fixed with the first portion by adhesive to electricallyconnected to the line layer; and electrically connecting the FPC on thefirst portion to the line layer.
 7. The method of claim 6, wherein thefingerprint sensor chip is contacted with the second portion of thesubstrate by adhesive.
 8. The method of claim 6, wherein the FPC isconnected on the first portion by welding.
 9. The method of claim 6,wherein the substrate is made of reinforced glass, sapphire or ceramicmaterial.
 10. The method of claim 6, further comprising electricallyconnecting the FPC with the line layer through welding with tin orconductive glue; wherein the adhesive is a heat conduction glue, and theblock is a metal or tin alloy conductive material.